Metal roof-supporting construction



June 4, 1963 R. L. PARSONS ErAL 3,092,221

METAL ROOF-SUPPORTING CONSTRUCTION Filed Aug. 7, 1959 2 Sheets-Sheet 1ATTORNEY June4, 1963 R. L. PARSONS Erm.

METAL RooFsuPPoRTING CONSTRUCTION 2 Sheets-Sheet 2 Filed Aug. 7, 1959 M5mw 2 L m w 0 Dn M B. H E W. e Q

A ORNEY United States Patent O 3,092,221 METAL ROF-SUPPRTINGCGNSTRUCTION Robert L. Parsons and Grover H. Bays, Parkersburg, W. Va.,assigner-s to Parkersburg-Aetna Corporation, Parkersburg, W. Va., acorporation of West Virginia Filed Aug. 7, 1959, Ser. No. 332,293 6Claims. (Cl. 189-36) This invention relates to a metal roof-supportingconstruction and has primarily to do with the means for connecting thepurlins to each other and to associated elements of a metal building.

An important object of the construction is to provide means for tyingadjacent roof purlins to each other to prevent them from deflecting inthe plane of the roof while erecting and to help take the horizontalcornponcnt of load such as snow and Wind, in the iinished buildingconstruction.

A further obiect is to provide a no fel combination of purlins andpurlin ties which so function that tension loads are carried throughoutthe purlin ties from one side of the building to the other side thereof.

A further object is to provide novel means for connecting the purlinties on opposite sides of each purlin to each other through the purlinto prevent deection of the purlin in the plane of the roof.

A further object is to provide among the purlin ties one which extendsacross the ridge of a roof to transfer tension loads between oppositesides of the roof.

A further object is to provide such a construction wherein the novelconnection of the purlin ties to each other, in combination with the tieextending across the ridge of the roof, so functions that loads orforces in the planes of the roof will be transferred from the roofcovering to one or more purlins which, in turn, will bear againstshoulders of purlin ties to be transferred through the connection ofsuch ties to higher purlin ties, thus distributing tension loads.

More specically, a further object is to provide novel means for soconnecting adjacent purlin ties through a purlin therebetween as toovercome a tendency of the purlin to turn or otherwise be displaced fromnormal position.

A further object is to provide such a combination of purlin and purlinties extending from the ridge of a roof to points spaced from oppositeeave struts or equivalent constructions and to connect the eave strutsto the adjacent purlins by threaded sag rods, thus preventingdispiacement of the eave struts and permitting the mounting of thelatter in straight lines.

A further object is to provide an arrangement of purlin ties relative tointervening purlins having webs perpendicular to the plane of theadjacent portion of the roof; to connect adjacent purlin ties throughthe purlin web by the use in each case of a single bolt, and to providepurlin ties having, in edect, shoulders engaging the web of the purlinto provide bracing of the top and bottom ilanges of the purlins.

Other objects and advantages of the invention will become apparentduring the course of the following description.

ln the drawings we have shown one embodiment of the invention, In thisshowing:

-FlGURE l is a partial plan View, largely diagrammatic, of a portion ofa roof-supporting structure embodying the present invention;

FGURE 2 is an end elevation of the same;

FIGURE 3 is a section taken substantially on line 3 3 of FIGURE l, partsbeing broken away;

FIGURE 4 is a detail fragmentary sectional view 0n line 4i-4i of FIGURE3;

ice

IFGURE 5 is a similar view on line 5-5 of IFIGURE 3;

FIGURE 6 is a similar View on line 6 6 of FIG- URE 3;

FIGURE 7 is a perspective view of ka purlin tie extending horizontallyat the ridge of the roof structure;

FGURE 8 is a similar view of one of the other purlin ties;

FIGURE 9 is a side elevation of one of the purlin sections; and

-FlGURE 10 is a perspective of a connection employed for securing eachend of the ridge purlin tie to adjacent pnrlin ties.

Referring to FlGURE 1, there are shown in broken lines opposite columns1t) of a building structure, columns at each side of the structure beingconnected by any suitable type of girts l1. The columns support girdersl?. shown in the present instance of the rigid bent type. lt willIbecome apparent, however, that the present invention is not limited touse with a girder of this type, since the girder may be of other types,for example, the top chord of a truss.

At each side of the structure is diagrammatically shown in FIGURE l aneave strut 14, and this particular element, extending longitudinally ofthe building, may be of any desired or suitable type. Extendinglongitudinally of the building and bolted or otherwise secured toadjacent girders 12 are a plurality of purlins, each indicated as a-whole by the numeral l5. The number of these purlins rWill depend, ofcourse, on the span of the root, and three of the purlins have beenshown in FIGURE 3. Each purlin comprises a veb 16 perpendicular to theplane of the roof and provided at its upper longitudinal edge with ayharige 17 parallel to the plane of the root" and a down-turned ange lparallel to the web le. The bottom of each purlin comprises a ilange 19parallel to the slope of the roof, and it is these flanges which aresecured to the girders, such anges being directly seated on the girders,as will be apparent in `FIGURE 2. The flanges 19 terminate at theiredges remote from the webs 16 in ilanges 2i) corresponding to the ilange18 and arranged parallel to the webs 15. The web of each purlin isslotted as at 22 intermediate and perpendicular to its longitudinaledges, as shown in FIGURE 9, for a purpose to be described.

lt will be apparent that the purlin sections 15 extend longitudinally ofthe building and the ends of these sections are suitably boltedtogether, preferably in overlapping relationship (not shown) over thetop flanges of the girders 12, thus providing in eect continuous purlinsfrom end to end of the building. Two of the purlins, indicated as awhole in FIGURE 2 by the numeral 24 and identical with those described,are arranged on opposite sides and slightly spaced from the ridge of theroof. A purlin tie 25 of the type shown in detail in FGURE 7 extendsbetween the purlins 24. Such tie has squared ends and includes a webportion 26 and longitudinal flanges 27 which preferably diverge slightlyfrom each 'other away from the web 26. Each end of the web 26 of eachpurlin tie 25 is provided centrally of the width thereof with a boltopening 2.8. The purlin tie 25 is tied to the next adjacent purlin tieoutwardly of the purlins 24 in a manner to be described.

The purlins at each side of the ridge of the roof are equidistantlyspaced from each other as shown in FIG- URE 2, such arrangement beingpreferred so that the purlin ties extending between adjacent pairs ofpurlins may be identical in the interest of economy in manufacture.Between each adjacent pair of purlins at opposite sides of the ridge isarranged a purlin tie or the type shown in FIGURE 8 and indicated as awhole by the 3 Y numeral 30. Each such purlin tie is similar inconstruction to the tie 25, being provided with a web 31 and upper andlower flanges 32, preferably slightly diverging from each other awayfrom the web 31. Each of the purlin ties 3i?, of course, is longer thanthe purlin tie 25 land has the anges at one end thereof cut away as at33 to form shoulders fora purpose to be described. The .cutting-away ofthe flanges 32 leaves the web 31 with a tongue or projecting web portion34 having a bolt opening 35 therein, the web 31 at the opposite endofthe tie being provided with a similar bolt opening 36. Each of thetongues 34 projects through one of the slots 22 in the adjacent purlinweb 16 with the shoulders 33 abutting the web 16. 'I'he'right-hand endof the next lower purlin tie, as viewed in FIGURE 8, has the flangeportion thereof forming shoulders abutting the opposite side of the.purlin web 16. The projecting tongue 34 fits within the channel of thenext adjacent purlin tie, being equal in width to the space between theflanges 32 adjaf cent the web 31 to provide a rigid joint between thepurlin ties at opposite sides of each purlin to prevent any rockingmovement lbetween adjacent purlin ties in the plane of their webs 31. Abolt 3S secures each projecting tongue 34 to the adjacent end of thenext adjacent purlin tie, the bolt'38 projecting through the boltopening 35 of the tongue 34 and through the bolt opening of the web ofthe next adjacent purlin tie, as will be apparent in FIGURES 3 and 4.

At each side of the ridge of the roof, the purlin tie adjacent each ofthe purlins 24 has -its squared end (the right-hand end in FIGURE 8)abutting the web 16 of such purlin. A T-shaped connecting plate 49(FIGURES 3 and :140) has its head portion 41 provided with bolt openings42, one of which receives a bolt 43V to secure it against the outer faceof the web 26 of the adjacent end of Ithe tie 25. The shank 45 of theconnection 41 projects through one of the slots 22 of the adjacentpur-lin web 16, and such shank corresponds in shape and size to each ofthe tongues 34 to lie within the channel of the adjacent purlin tie 3i).The shank 45 has a bolt opening 46 Vadapted lto register with the boltiopening 36 of the adjacent purlin tie 30, and a bolt 47 connects theseelements together, as shown in FIGURES 3 and 6.

As previously stated, the purlin ties 30 are preferably identical toeach other in the interest of economy in manufacture. Therefore, itseldom occurs that the space between the outermost purlin at each sideof the roof and the eave strut 14 is equal to the space between adjacentpairs of purlins. Thus it is impracticable for this reason to use apurlintie between each eave strut and the adjacent purlin, and it isalso impracticable for an additional reason to be referred to.

Each eave strut 14 may be of the cross-sect-ional type shown in FIGURE3, terminating at the top thereof in a depending flange 49 at a slightangle to the vertical, as shown. A sag rod 50, threaded at both ends,projects through the flan-ge 49 and has a nut 51 threaded thereon. 'I'heother end of the sag rod 50 (FIGURE 5) projects through one ange 52 ofan angle rail 53, the other flange 54 of which seats against the web 16of the adjacent purlin 15. Within ythe ange 52. a nut 55 is threaded onthe sag rod 50'. The next adjacent purlin tie 30 has its tongue 34projecting through the adjacent slot 22 of the web 16 and bolted as at56 to the flange 54. rIhe free end of the ila-nge 54 forms, in effect, ashoulder engaging against the adjacent face of the web 16, while Itheshoulders 33 of the flanges 32 of the next purlin tie 30 seat againstthe opposite face of the web 16. Such web is arranged between engagingshoulders in the saune manner as the remaining purlin webs 16 areengaged by adjacent end portions of adjacent purlin ties 31. Thus thesag rod 50 and its angle rail 53 constitute, in eiect, a purlin tie.Similarly, each purlin tie 25 (FIGURES 3 and 7) and its associated tieplates 40 constitute a purlin tie connected lbetween the webs of thepurlin-s 24.

Operation inserted in the next 4webs 16 of the adjacent purlins 15,

whereupon the next purlin ties 30 will be placed in position and boltedto the tongues 34 of the preceding purlin ties as at 38. This procedureis followed throughout successive purlins until the lowermost purlins atopposite sides of the roof are in position. The latter purlins are thenxed with respect to the remaining structure by bolting the tongue 34 ofthe adjacent tie 30 to the flange 54 (FIGURE 5) as at 56. The sag rod 50performs an important function in the structure. It is desired, ofcourse, that each eave strut 14 be maintained straight, and due tomanufactuning tolerances, etc., there will be some variation in thedistance from each iange 52 to the ange 49 of the adjacent eave strut.By employing the sag rod 50, the nuts 51 and 55 may be suitablytightened to take up any slack between the elements and to straighten.the eave strut 14 at each side of the building. After the assemblinghas been completed as described, the roof coveringshee-ts are placedover the flanges 17 and secured in position. It will be noted that thesloping top of the eave strut 14 in FIGURE 3 lies in the plane of thepurlin anges 15 to support the outer edge portions of the roof coveringsheets.

Each sag rod is a tension member and prevents the eave strut fromspreading away from the adjacent purlin due to any load directed towardthe eave in the plane of the roof. Moreover, 'tension in either sag rodwill place in tension the .purlin ties entirely across the building,such tension being transmitted through bolts 56, 38, 47 and 43. Theequal spacing of the purlins permits the manufacture of quantities ofidentical purlin ties for predetermined roof loadings. The use of thesag rod has the additional advantage of eliminating the necessity ofusing a purlin tie between Veach eave strut 1'4 and the adjacent purlinand also eliminates the problem which would be involved in connectingsuch elements together.

The equal spacing of the purlins will vary with diier` ent roof loadingsdepending upon the strength of the roof covering. For example, someroofs may be designed for 20 pounds per lsquare foot of snow load andothers for 30 pounds per square foot. With the same roof covering, thepurlins will have to be spaced closer. for 30-pound loading than for20-pound loading, as will be apparent. In each case, however, the purlinspacing will be kept equal from the ridge toward the eave by means ofidentical purlin ties. These ties are primarily tension members, butwill withstand sorne vcompression and bending.

The tendency for the purlins to deflect or bend in the plane of the roofwill be prevented by the horizontal purlin tie at the ridge and thesloping ties at either side of the ridge. The loads or forces in theplane of the roof will be transferred from the roof covering to thepurlins which, in turn, will bear `against the anges of the squared endsof the purlin ties (the right-'hand end n- FIGURE 8) and tension loadswill be transferred through the tongues 34 of the next higher purlinties.

It will be noted that the reduced ends or tongues 34 and the width ofthe shank 45 (FIGURE 10) are the same as the inside dimension of thepurlin ties between the edge anges thereof. Accordingly, when the bolts38 and 47 are tightened, the ends 34 or 45 will be wedged in thechannels of the purlin ties, thus preventing rocking of the purlin tiesin the planes of their Webs. The shoulders formed on the ends of thepurlin ties bear against the webs 16 of the purlins and accordingly tendto resist the slightest rotation or rocking of the purlin webs.

The degree of resistance to rotation `afforded by the bearing of theshoulders of the purlin ties on the purlin webs is dependent upon thedepth of each tie as well as proper orientation of the tie. In thepresent construction, the depth of each tie is sucient to overcomepurlin rotational tendencies without overstressing the shoulders of thepurlin ties which are in bearing. Moreover, the orientation of eachpurlin tie is with the web of the tie perpendicular to the longitudinalcenter line of the adjacent purlin, this being the most etectivearrangement of parts for maximum resistance to rotation of each purlin.The location of each purlin tie with its end centrally of the width ofeach web 16 provides lateral bracing for the top and bottom anges of thepurlins.

The present construction not only resists loads from the roof coveringdue to snow, wind and erection, but also resists the weight of workmenor other loads on the purlins between the girders. Such loads causeundue rotation and bending of the flanges of the purlins. The purlinties hold the purlins in alinement and prevent rotation, to facilitatethe installation of the roof covering and provide increased safety forworkmen.

It is to be understood that the form of the invention shown anddescribed is to be taken as a preferred example of the same and thatvarious changes in the shape, size, and arrangement of the parts may bemade as do not depart from the spirit of the invention or the scope ofthe appended claims.

We claim:

1. In a roof construction wherein the roof slopes `downwardly inopposite directions away from a ridge, a plurality of purlins arrangedat each side of said ridge and spaced lfrom and parallel to each otherand to said ridge, two of said purlins being arranged at opposite sidesof said ridge and equidistantly spaced therefrom, said two purlinshaving webs perpendicular to the respective slopes of the roof andprovided with sets of slots transversely of such webs, purlin tiesconnecting adjacent pairs of said purlins, horizontal purlin tiesassociated with each of said slots and extending between said twopurlins, all of said purlin ties having webs lying -in vertical planes,a tongue at each end of each horizontal purlin tie forming acontinuation of the web thereof projecting through and fitting one ofsaid slots, and means connecting said tongues to the respective purlinties at the remote sides of said two purlins, the ends of the webs ofsaid purlin ties at the remote sides of said two purlin .ties abuttingthe webs thereof offset to one side of the respective slots.

2. A construction according to claim 1 wherein each purlin tie extendingbetween said two purlins is horizontal and comprises a horizontal purlintie body and a T-shaped plate connected to each end of such body havinga head portion connected to the web of said purlin tie body and havingits shank constituting the tongue of the last-mentioned purlin, theheads of Said plates abutting the adjacent sides of said two purlins.

3. in a root construction wherein the roof slopes downwardly in oppositedirections away from a ridge, a plurality of purlins arranged at eachside of said ridge and spaced from and parallel to each other and tosaid ridge, two of said purlins being arranged at opposite sides of saidridge and equidistantly spaced therefrom, each purlin having a webperpendicular to the adjacent slope of the roof and provided with spacedslots transversely of such webs, each slot in each purlin web lying in`a common plane with slots in the other purlin webs, purlin ties -aI-ranged between each adjacent pair of purlins and each provided with aweb lying in a perpendicular plane and edge anges, the purlin tiesbetween said two purlins being horizontal and each having tongues atopposite ends thereof forming continuations of the web thereofprojecting through and fitting slots in the respective purlins of saidtwo purlins, each of the other purlin ties having a tongue in the planeof the web thereof at the end thereof remote from said two purlin tiesprojecting through and litting one of said slots and overlying the webof the next adjacent purlin tie, and bolts passing through each tongueand the purlin tie web which it overlies, adjacent ends of each adjacentpair of purlin ties at each slope of the web having shoulders engagingthe purlin web therebetween.

4. A construction according to claim 3, wherein the anges of each purlintie project from the same side of the web thereof whereby each purlintie is of channel section, each of said tongues being of a width equalt0 the distance between said flanges to be engaged thereby to preventrelative rocking of ladjacent purlin .ties in the planes of the Websthereof.

5. In a roof construction wherein the roof slopes downwardly in oppositedirections away from a ridge, a plurality of purlins larranged `at eachside of said ridge, and spaced from and parallel to each other and tosaid ridge, two of said purlins being arranged at opposite sides of saidridge and equidistantly spaced therefrom, all of said purlins havingwebs perpendicular to their respective slopes of the roof and providedwith sets `of slots transversely of such webs, the slots of each setlying ina common vertical plane, purlin ties connecting adjacent pairsof purlins at each side of said ridge, horizontal purlin ties associatedwith the slots of said two purlins, said horizontal purlin ties beingconnected to the adjacent ends of the adjacent purlin ties through the-slots in said two purlins, each of the remaining purlin ties having asquared end engaging the web of the adjacent purlin, the other end ofeach such purlin tie having a tongue forming -a continuation of its weband projecting through the adjacent slot in the adjacent purlin, andoverlying the web of the next adjacent purlin tie, each tongue tting theassociated slot and being of a width less than the width of the web ofwhich it forms a continuation, whereby portions of each such web beyondthe edges of the associated tongue seat against the web of theassociated purlin, and means xing each tongue to the purlin tie webwhich it overlies whereby said purlin ties act in eifect as `acontinuous tension member from side to side of the roof.

6. A construction according to claim 5, wherein each purlin tie isprovided with longitudinal edge flanges projecting from the same side ofthe web thereof, whereby each purlin tie is of channel section, each ofsaid tongues being of a width equal to the distance between said angesto be engaged thereby to prevent relative rocking of adjacent purlinties in the plane of the webs thereof.

References Cited in the le of this patent UNITED STATES PATENTS1,225,727 Brogden May 8, 1917 1,843,356 Carlough Feb. 2, 1932 2,549,816Johnson Apr. 24, 11951 2,689,630 Drury Sept. 21, 1954 2,692,033 JaynessOct. 19, 1954 2,722,901 Johnson et al, Nov. 8, 1955 2,815,831 Hield etal Dec. 10, 1957 2,871,997 Simpson et al Feb. 3, 1959 2,903,z104 BrownSept. 8, 1959 FOREIGN PATENTS 434,281 Italy Apr. 24, 1948

1. IN A ROOF CONSTRUCTION WHEREIN THE ROOF SLOPES DOWNWARDLY IN OPPOSITE DIRECTIONS AWAY FROM A RIDGE, A PLURALITY OF PURLINS ARANGED AT EACH SIDE OF SAID RIDGE AND SPACED FROM AND PARALLEL TO EACH OTHER AND TO SAID RIDGE, TWO OF SAID PURLINS BEING ARRANGED AT OPPOSITE SIDES OF SAID RIDGE AND EQUIDISTANTLY SPACED THEREFROM, SAID TWO PURLINS HAVING WEBS PERPENDICULAR TO THE RESPECTIVE SLOPES OF THE ROOF AND PROVIDED WITH SETS OF SLOTS TRANSVERSELY OF SUCH WEBS, PURLIN TIES CONNECTING ADJACENT PAIRS OF SAID PURLINS, HORIZONTAL PURLIN TIES ASSOCIATED WITH EACH OF SAID SLOTS AND EXTENDING BETWEEN SAID TWO PURLINS, ALL OF SAID PURLIN TIES HAVING WEBS LYING IN VERTICAL PLANES, A TONGUE AT EACH END OF EACH HORIZONTAL PURLIN TIE FORMING A CONTINUATION OF THE WEB THEREOF PROJECTING THROUGH AND FITTING ONE OF SAID SLOTS, AND MEANS CONNECTING SAID TONGUES TO THE RESPECTIVE PURLIN TIES AT THE REMOTE SIDES OF SAID TWO PURLINS THE ENDS OF THE WEBS OF SAID PURLIN TIES AT THE REMOTE SIDES OF SAID TWO PURLIN TIES ABUTTING THE WEBS THEREOF OFFSET TO ONE SIDE OF THE RESPECTIVE SLOTS. 